GET /correlation

$0.05 USDC

How closely 14 large perpetuals move with BTC: the Pearson correlation of hourly returns over one window, by default the last 30 hours (30 returns), not 30 days. Returns are joined on candle time; a coin whose newest candle lags BTC’s is left out rather than mismatched. Each correlation comes with its sample size and standard error, so a noisy 30-hour figure can be told apart from a 30-day one.

Coins: BTC, ETH, SOL, DOGE, XRP, AVAX, LINK, ARB, OP, SUI, NEAR, INJ, APT, ADA, PEPE.

Request

GET https://api.cerebruspulse.xyz/correlation

Query Parameters

Parameter	Type	Default	Description
`window`	string	`30h`	`30h` (30 hourly returns), `7d` (168) or `30d` (719). Any other value is refused with 400 before any price is quoted.

Response

Field	Type	Description
`endpoint`	string	`correlation`
`timestamp_iso`	string	When the response was computed (UTC)
`btc_correlation.<coin>`	number \| null	Pearson r of the coin’s 1h returns against BTC’s, −1 to 1. `BTC` is `1.0`. Null when the coin lags BTC, lacks candles, or has fewer than max(20, window / 2) joined returns
`correlation_stats.<coin>`	object	For each coin with a correlation: `n` (joined returns used) and `stderr` (`(1 − r²) / √(n − 1)`)
`average_correlation`	number \| null	Mean of the non-null correlations, BTC excluded
`regime`	string	`CORRELATED` (average > 0.7), `DECORRELATED` (< 0.3), `MIXED`, or `UNKNOWN`
`sector_averages.<sector>`	number	Mean correlation per sector with data: `L1` (ETH, SOL, AVAX, NEAR, APT, SUI, ADA), `L2` (ARB, OP), `DeFi` (LINK, INJ), `Meme` (DOGE, PEPE)
`meta`	object	Common metadata (Response Schemas)
`meta.offering`	string	`pulse_correlation`
`meta.coins_analyzed`	number	Coins with a correlation, BTC included
`meta.window`	string	The window used
`meta.lookback_bars`	number	Hourly returns in the window
`meta.timeframe`	string	`1h`
`meta.method`	string	The method, as text
`meta.lagging_coins`	array	Coins left out because their newest candle is older than BTC’s (also flagged in `meta.warnings` as `lagging_coins`)

meta.as_of.candles_1h is the close of BTC’s newest candle, which every correlated coin reaches.

Example

GET /correlation: real engine output on market data captured at 2026-09-24 17:05 UTC. Lists are cut to 3 items. Live responses may also carry meta.disclaimer, which the gateway adds.

{
  "endpoint": "correlation",
  "timestamp_iso": "2026-09-24T17:05:00Z",
  "btc_correlation": {
    "BTC": 1,
    "ETH": 0.9319,
    "SOL": null,
    "DOGE": 0.8839,
    "XRP": null,
    "AVAX": null,
    "LINK": null,
    "ARB": null,
    "OP": null,
    "SUI": null,
    "NEAR": null,
    "INJ": null,
    "APT": null,
    "ADA": null,
    "PEPE": null
  },
  "correlation_stats": {
    "ETH": {
      "n": 30,
      "stderr": 0.0244
    },
    "DOGE": {
      "n": 30,
      "stderr": 0.0406
    }
  },
  "average_correlation": 0.9079,
  "regime": "CORRELATED",
  "sector_averages": {
    "L1": 0.9319,
    "Meme": 0.8839
  },
  "meta": {
    "provider": "Cerebrus Pulse",
    "offering": "pulse_correlation",
    "execution_ms": 0,
    "coins_analyzed": 3,
    "window": "30h",
    "lookback_bars": 30,
    "timeframe": "1h",
    "method": "Pearson r of 1h returns joined on candle time; stderr = (1 - r^2) / sqrt(n - 1)",
    "lagging_coins": [],
    "as_of": {
      "candles_1h": "2026-09-24T17:00:00Z"
    },
    "sources": [
      {
        "name": "Hyperliquid",
        "url": "https://hyperliquid.xyz"
      }
    ]
  }
}

This capture held 1h candles for BTC, ETH and DOGE only, so the other coins read null and coins_analyzed is 3. A live response fills every coin that has enough data.

Errors

Status	Reason
400	`window` not one of `30h`, `7d`, `30d` (before any price is quoted), or not enough BTC candles (not charged)
402	Payment required (the standard x402 flow)
429	Rate limit exceeded
503	Service disabled, payments down, or the candle feed is missing or stale; no price is quoted
504	Engine timeout (not charged)